Atmel AVR XMEGA AU series User Manual

148
8331B–AVR–03/12
Atmel AVR XMEGA AU
Figure 13-8. Synchronization when reading a pin value.
13.5 Input Sense Configuration
Input sensing is used to detect an edge or level on the I/O pin input. The different sense configu-
rations that are available for each pin are detection of a rising edge, falling edge, or any edge or
detection of a low level. High level can be detected by using the inverted input configuration.
Input sensing can be used to trigger interrupt requests (IREQ) or events when there is a change
on the pin.
The I/O pins support synchronous and asynchronous input sensing. Synchronous sensing
requires the presence of the peripheral clock, while asynchronous sensing does not require any
clock.
Figure 13-9. Input sensing.
PERIPHERAL CLK
INSTRUCTIONS
SYNCHRONIZER FLIPFLOP
IN
r17
xxx xxx lds r17, PORTx+IN
t
pd, max
t
pd, min
0x00 0xFF
INVERTED I/O
Interrupt
Control
IREQ
Event
Pn
D
Q
R
D
Q
R
Synchronizer
INn
EDGE
DETECT
Asynchronous sensing
Synchronous sensing
EDGE
DETECT

Atmel AVR XMEGA AU series Specifications

General

Brand	Atmel
Model	AVR XMEGA AU series
Category	Microcontrollers
Language	English